不同覆盖栽培糜子籽粒灌浆期淀粉酶活性变化

为研究糜子开花后籽粒灌浆期间淀粉合成相关酶活性的变化及淀粉积累特征,并分析两者之间的关系;探寻糜子在干旱地区的最佳覆盖栽培模式。以粳性糜子品种榆糜2号为材料,采用秸秆覆盖、起垄覆膜、双沟覆膜和全膜覆盖处理,并以露地栽培为对照,测定籽粒灌浆期间淀粉合成相关酶活性的变化及淀粉积累动态。结果表明,覆盖栽培糜子籽粒灌浆前、中期ADP-葡萄糖焦磷酸化酶(AGPP)、水溶性淀粉合成酶(SSS)、颗粒结合性淀粉合成酶(GBSS)及淀粉分支酶(Q酶)活性均显著高于露地栽培(P0.05),且籽粒淀粉积累速率较快,最终淀粉含量高于露地栽培,其中全膜覆盖效果最佳,其籽粒中支链淀粉积累量的增加率达16.62%(P0.05),直链淀粉增加率9.08%,千粒质量增加率6.16%(P0.05)。但覆盖栽培没有改变AGPP、SSS、GBSS和Q酶活性的变化趋势(单峰曲线),没有影响酶活性峰值出现时间,AGPP和GBSS峰值出现在花后20d左右,SSS和Q酶峰值出现在花后15d左右。相关分析表明,糜子籽粒支链淀粉与SSS和Q酶活性呈极显著正相关,与AGPP酶活性呈显著正相关;直链淀粉与GBSS和AGPP酶活性呈显著或极显著正相关;总淀粉积累速率与AGPP、GBSS、SSS和Q酶活性呈显著或极显著正相关。

Dynamic changes of starch synthesis enzymes activities of Panicum miliaceum L. grain during the filling stage under different mulching cultivation

The purpose of the study is to investigate the effect of different mulching cultivation on the activity changes of enzymes involved in Panicum miliaceum L.grain starch biosynthesis and the characteristics of starch accumulation in grains,to analyze the relationship between them,and to find the best mulching cultivation in arid area.Yu-mi 2 (Panicum miliaceum L.) as the material was used in the study which was cultivated under four types of mulching cultivation and one type without mulching (LD).The four types of mulching cultivation include straw mulching (JG),plastic film mulching with two grooves (SG),plastic film mulching with ridging (QL) and plastic film mulching the whole field (QM).The results indicated that the activities of adenosine diphosphorate glucose pyrophrylase (AGPP),soluble starch synthase (SSS),granule-bound starch synthase (GBSS),and Q enzyme changed in the pattern of a single-peak curve during grain filling stage,the activity peaks of AGPP and GBSS appear in 20 days after the anthesis,and the activity peaks of SSS and Q enzyme appear in 15 days after the anthesis.The activities of AGPP,SSS,GBSS and Q enzyme were all higher in mulching cultivation than that in LD (P<0.05),the starch content is higher than that in LD cultivation,and the QM cultivation was the best (amylopectin accumulation increased 16.62%,amylase accumulation increased 9.08% and the 1000-grain weight increased 6.16%).The accumulation rate of amylopectin was significantly or highly significantly correlated with the activities of AGPP,SSS and Q enzyme,the accumulation rate of amylose was significantly correlated with the activities of AGPP and GBSS,and the accumulation rate of total starch was significantly or highly significantly correlated with the activities of AGPP,SSS,GBSS and Q enzyme.